Figure 1: Illustration of the bias in the estimated BHMF derived from mass estimates. Shown is the true mass function (thick solid black line) for a simulated sample, and the mass function derived from the mass estimateswhen the statistical error in the mass estimates is 0.3 dex (red dashed line), 0.4 dex (green dot-dashed line), and 0.5 dex (solid blue thin line). The mass function estimated from the mass estimates is biased, especially at the high-MBH end and for large statistical error.